1911] Teller, Fossils from the Palceozoic Formations. 177 



specimens which have been used in the same stndy for the pur- 

 pose of comparison may be regarded as collateral types. 



Prof Charles Schuchert says that these citations show clearly 

 that a type is not always restricted to a single specimen selected 

 by an author but also applies to several or even to all the specimens 

 contained in the original lot. Because of the general imperfection 

 of fossils much of the original material is usually accepted as types, 

 but when specimens are figured as is generally the custom, it is 

 good practice to regard these alone as types. 



All type specimens in biology may be divided into two groups, 

 "type material" and "typical specimens." By various writers these 

 have been divided into a number of sub-types known by them as, 

 Holotype, Cotype (or Syntypc), Paraptype, Lcctotype, Chirotype, 

 Plesiotype, Neotype and Heautotype, all tending to cause more or 

 less confusion to the one not a thorough specialist, and terms to 

 which the most of them pay little or no attention. The only real 

 purpose of so many type terms would seem to suggest the multi- 

 plication of type specimens, and many of these are now obsolete 

 terms which have been rarely or never used by those who pro- 

 posed them although some of them are now commonly used in 

 the catalogue of the types in the Smithsonian Institution, and the 

 only purpose of such use seems to be to burden science with a 

 useless terminology. One of the most serious objections to these 

 terms is the discouraging effect they must have not only upon the 

 student but specialists in general and the confusion that must arise 

 in the minds of both as to what term may refer to the true types 

 and what do not, as any other term than that of type for a type 

 specimen is entirely unnecessary at any time. 



Prof. C. Hart Merriam, writing on this subject says, "type 

 specimens being units of comparison should from the nature of the 

 case be single, not multiple ; it is the common experience of nat- 



